Since launching brands The Row and Elizabeth and James, the sisters have been honored to receive major fashion awards for their fearless sense of style. Never ones to put boundaries around fashion, they've inspired numerous trends, including choker necklaces, big sunglasses, and oversized layers.
Keep scrolling to see how their fashion sense has played out over the last 18 years.
In 2000, Mary-Kate and Ashley Olsen attended the launch event for a planner they designed — perhaps the kick-start to their future as fashion designers.
It was the start of the choker trend.Hulton Archive/Getty Images
Their zigzag hair parts, slightly sophisticated jewel-toned holiday dresses, and coordinating chokers all sum up the early 2000s holiday aesthetic.
The twins stuck to their signature matching strategy in 2001 for NYSYNC's party celebrating the release of their CD "Celebrity."
How to dress for an NYSNC party.Kevin Winter/Getty Images
In 2002, the Olsens were photographed in London as they presented a check to the BBC for Children in Need.
They went casual in denim.Anthony Harvey/Getty Images
The twins kept their neutral blouses sweet and simple with slight ruffles and a sheer print. However, the real accessorizing played out with their true blue jeans and oversized brown leather belts, complete with gold medallions and turquoise stones.
Mary-Kate and Ashley spoke with the press in black and white complementary outfits just before the 2003 MTV Video Music Awards in New York City.
They each paired a turquoise accessory with their neutral outfits.Mark Mainz/Getty Images
Save for minor accessory choices, the Olsen sisters' New York style is still covetable in 2017. Wide-leg pants are a city girl staple, and a silk wrap-blouse is eternally chic. They were also way ahead of the "bronde" hair trend.
In 2004, the Olsen twins put on party dresses for the Los Angeles premiere of their film "New York Minute."
A classic look for the duo.Kevin Winter/Getty Images
The actress sisters wore very different dresses to their movie premiere, but were cohesive with a '20s fashion theme. Mary-Kate layered Chanel pearls over her lacy eyelet dress, and Ashley went for a pretty silver slip, which she styled with silver jewelry.
The sisters hit the red carpet in New York City for another premiere of their movie "New York Minute" during the 2004 Tribeca Film Festival.
Mary-Kate deepened her hair to a warm brown tone that set her apart from the twins' signature blonde.Evan Agostini/Getty Images
The dainty straps on Ashley's bronze slip dress were echoed by the thin band on her strappy sandals. Mary-Kate went for a busier look, wearing a brown polka-dot dress with candy-colored pointed-toe heels.
In 2005, Mary-Kate and Ashley Olsen made their debut at the Met Gala Celebrating Chanel in New York City.
Their styles started to become more apparent.Peter Kramer/Getty Images
For their Met Gala debut, the sisters styled their gently tousled curls with soft, flowing dresses. Mary-Kate paired a white embroidered dress with red beads and a stack of gold bracelets. Ashley opted for a gold midi dress with an iridescent pattern and a pale pink ribbon that cinched at the waist.
Later that year, they hosted an event with Lucky Magazine in Los Angeles.
They matched their babydoll dresses with black pumps.Mark Mainz/Getty Images
Mary-Kate Olsen layered her beige dress with black tights, while Ashley kept her ivory dress plain and simple.
The actresses attended Olympus Fashion Week in 2006 in New York City.
This is the same year the Olsen twins launched their first fashion line, The Row.Gustavo Caballero/Getty Images
The Olsen twins channeled their inner New York City glam with two edgy dresses. Ashley toughened her rosy velvet dress with a cropped leather jacket, while Mary-Kate opted for a sheer black dress complete with butterfly sleeves and a hint of sparkle.
The Olsens returned to their twinning style in 2007 at the 25th Anniversary of the CFDA Fashion Awards.
Both sisters opted for a smoky eye with a nude lip.Evan Agostini/Getty Images
Mary-Kate and Ashley displayed their sophisticated taste wearing complementary black and white ensembles with plunging necklines, detailed waistlines, and wide-leg silhouettes.
The Olsens were photographed leaving the Chanel fashion show in 2008.
They matched in oversized sunglasses at Paris Fashion Week.Julien M. Hekimian/Getty Images
The Olsen twins are notorious for their stylish sunglasses, and nothing is more memorable than their contributions to the oversized trend.
The stylish sisters also played with proportions for their looks at a 2008 book signing in California.
Oversized accessories, like rings and belts, were a clear indicator of early 2000s fashion.Frazer Harrison/Getty Images
Ashley offset her leather mini skirt and chunky platform heels with an oversized velvet outwear piece. Mary-Kate also displayed a leather look, rocking peep-toe leather sandals that zipped up the front of her ankles. She accented her beige dress with a cherry red belt that cinched at the waist.
In a wild display of pattern and color, the Olsens attended "The Museum of Modern Art Film Benefit: A Tribute To Tim Burton" in 2009.
The sisters carried ordinary briefcase bags with their quirky outfits.Bryan Bedder/Getty Images
Ashley Olsen gave serious Carrie Bradshaw vibes in a turquoise dress that hit just above her ankles and a classic black peacoat with yellow pointed-toe Manolo Blahnik heels. Mary-Kate went even bolder in a large leopard print coat, a black brimmed hat, and a vampy oxblood red lip.
At the 2010 ELLE Style Awards, the Olsen twins brought fur and tulle to the red carpet.
It takes true fashionistas to rock sheer tulle gowns with bold fur coats.Gareth Cattermole/Getty Images
Mary-Kate took a sheer black tulle gown and layered it beneath a cozy black fur coat, while her sister took a softer approach, wearing a nude and blue tulle dress. She too bundled up in a cropped coat — though hers was dark red.
Just a few months later, they shared a twinning moment at a Broadway premiere in New York City.
Back to black.Will Ragozzino/Getty Images
Each of the Olsen twins wore stark black outfits with dark oversized sunglasses. Ashley Olsen selected angular frames to pair with her sweet ribbon dress. Mary-Kate wore large round glasses with a dramatic coat and a sheer dress — similar to the look she wore at the ELLE Style Awards.
The Row designers wore their own label to the 2011 CFDA Fashion Awards.
Both sisters brightened their traditionally golden locks to a cool platinum tone.Andrew H. Walker/Getty Images
Ashley's powdery blue tea-length dress revealed yet another pair of golden Manolo Blahnik heels. Mary-Kate fearlessly donned a bright golden blazer and a black satin dress that trailed behind her metallic ankle-strap heels.
Mary-Kate and Ashley Olsen were honored with the 2012 Womenswear Designers of the Year award at the CFDA Fashion Awards.
They definitely look the part.Jamie McCarthy/Getty Images
Ashley attended the stylish event in a magenta dress with a sweeping ruffle across the front. Mary-Kate went for a darker look in an entirely black ensemble and a deep brown hair color.
The Olsens kept it simple at the Lexus Design Disrupted Fashion Event in 2013.
True to New York style, the twins wore all black.Taylor Hill/Getty Images
The Olsens returned to their roots with chic dark outfits, smoky eyes, and nude lipstick. Pretty tie-front heels added a touch of intrigue to their overall minimalistic looks.
They brought a beautiful maturity to the "Charles James: Beyond Fashion" Costume Institute Gala at the Metropolitan Museum of Art in 2014.
Tasteful and timeless red carpet looks.Dimitrios Kambouris/Getty Images
Taking a more understated and conservative approach to the red carpet, the Olsen twins once again nailed the art of fashion. Ashley's gold button-down dress was classic, while Mary-Kate's striped gown with sheer sleeves looks like it pulled inspiration from menswear.
The Olsens proved victorious for the second time at the 2015 CFDA Fashion Awards after being named the Womenswear Designers of the Year.
The muted color palette has become an Olsen twin signature — and they own it every time.Larry Busacca/Getty Images
In powerful looks that can only be described as cool, Mary-Kate and Ashley proved to be the ultimate fashion champions with Chanel flats and loafers, along with dangling diamond earrings.
The Olsens returned to the Met Gala red carpet for the 2016 theme of "Manus x Machina: Fashion In An Age Of Technology."
They are the queens of monotone fashion.Larry Busacca/Getty Images
Ashley wore a neutral dress that streamlined straight to the ground beneath a gold, oversized outwear garment. Mary-Kate opted for something even simpler, a black long-sleeve dress similar in nature to the style of her sister's.
For the 2017 Met Gala honoring Rei Kawakubo/Commes des Garcons, the twins abandoned their all-black event looks.
The sisters wore boho dresses that were heavy on the details.Theo Wargo/Getty Images For US Weekly
Neutral tones were at the core of the Olsens' 2017 Met Gala ensembles. Both twins wore nude lace dresses and let their black undergarments peek through. Ashley paired hers with an elaborate jacket, while Mary-Kate accessorized with a large necklace.
Their ensembles for the 2017 CFDA Fashion Awards in June 2017 were classic yet casual looks for the sister duo.
This was a classic Olsen look.Dimitrios Kambouris/Getty Images
Ashley opted for a long black coat dress, while Mary-Kate went with an oversized white button-up and black pants.
They pulled out all the stops once again for the 2018 Met Gala in May.
Mary Kate Olsen and Ashley Olsen attend the Met Gala 2018.Neilson Barnard/Getty Images
Mary-Kate paired her black wrap dress with a large statement necklace, while Ashley went with a similarly flowing gown featuring red, black, and gold stripes which she paired with a jeweled headpiece.
Sign up here to get INSIDER's favorite stories straight to your inbox.
Read next
Business Insider tells the innovative stories you want to know
Business Insider tells the innovative stories you want to know
Business Insider tells the innovative stories you want to know
Business Insider tells the innovative stories you want to know
